Due to the aging baby-boom generation and improvements in healthcare, the average age of the US population is increasing and is projected to continue to increase for decades. The demand for assistive technologies such as electric powered wheelchairs (“EPW” or “EPWs”) and scooters have kept close pace with the increasing elderly population, as demonstrated by the sharp increases in Medicare spending on these devices. Scooter and EPW use increased by an average of 25% between the years 2002 and 2003.
Currently, the devices available fall into two basic categories: (1) high-cost, highly maneuverable EPWs ($5000-$30,000) and (2) lower-cost scooters ($2000-$3000), technically known as power operated vehicles (“POV” or “POVs”). The POVs have less maneuverability and stability than the EPWs. POVs provide functional mobility in well-built, open spaces—such as shopping malls, paved roads and sidewalks. The POVs, however, provide little to no mobility in the home or over rough terrain. While EPWs can provide functional mobility in all locations, insurance companies typically will only reimburse the high cost of these devices if an individual cannot safely ambulate in their home. Further, one of the efforts to curb increasing healthcare costs has been to make EPW eligibility criteria more stringent, which has also restricted many individuals from receiving them.
Between 1969 and 1995, the use of wheelchairs has quadrupled (see FIG. 1). Survey results from non-institutionalized users, from the National Health Information Survey on Disability (NHIS-D, Phase 1 & Phase 2), taken between 1994-1997 reveal that there are 1.5 million manual wheelchair users, 155,000 EPW users, and 142,000 POV users. In summary, there were a total of 1.7 million mobility device users from 1994-1997 in the United States. More recent data, recorded by the Census Bureau's Survey of Income and Program Participation (or “SIPP”), estimated there were 2.3 million mobility device (MWC, EPW, and POV) users in 1999 (see FIG. 1). Using a linear extrapolation of this data, it is projected that 4.3 million mobility devices will be in use by the year 2010, 392,000 and 359,000 of which would be EPWs and POVs, respectively (see FIG. 2). This is likely a conservative estimate, considering the strong positive correlation between age and mobility device use, and the 76 million people retiring from the baby boomer generation, which will results in a rapid expansion of individuals over 65 years of age. Since POV use is more common than EPW use among individuals over the age of 65, the demand for POVs is likely to grow disproportionately compared to other wheeled mobility devices as the baby boomers retire.
A low cost, highly functional mobility vehicle, as provided in the present invention, addresses the swelling growth of medical expenditures in the US. Besides curbing medical expenditures, the large numbers of uninsured or underinsured individuals need to be able to obtain this technology to more fully participate in society. The incidence of this unmet need is startling. In 1990, 1 in 5 (or 20%) of individuals who needed assistive technologies could not procure such devices because of the high price and their lack of sufficient insurance. If the prices of these vehicles can be reduced, more people will be able to access these technologies.
Apart from the substantial need for low-cost mobility devices in the US, there is an enormous need for mobility devices in lower income countries where cost is the most important factor in determining whether a technology can be adopted. As the economies of these low income countries expand, as is occurring in India and China, powered mobility vehicles may soon be an option to allow older individuals or those with disabilities to become more integrated into society. However, the technology must be highly functional and low-cost, as is the present invention. Cost, beyond any other factor, such as maneuverability, comfort, fit, etc., defines the size of the market for mobility devices, as the actual need for the devices are overwhelming.
There are both technical and cost trade-offs for users when they are choosing or being prescribed either a POV (FIG. 3A) or an EPW (FIG. 3B). In terms of user safety, stability is one of the most important factors. Structurally, POVs are longer and narrower than most EPWs, which compromise lateral stability. At first glance, the POV design may appear to increase forward and rearward stability, but because the majority of the mass in the POV is towards the rear of the device, and is above the rear axle, rearward stability of POVs is typically worse than that of EPWs.
Adding to these structurally-related stability issues are the differences in the way the POVs and EPWs maneuver (see FIGS. 4A and 4B). Because of the front wheel steering, and the relatively long wheelbase, POVs make wide sweeping turns which subjects them to high lateral tipping forces (FIG. 4A, top arrow), significantly decreasing the stability of the devices. A similar turn, made by an EPW user, is much more stable because they turn with differential speed control of the wheels (see FIG. 4B, bottom arrow). When sharp turns (e.g., no forward velocity) are made, the EPW rotates about an axis, within its own footprint, resulting in little to no lateral tipping force, compared to the large lateral tipping forces on the POVs during sharp maneuvering. As the forward speed of the EPW increases, lateral force on the EPW increases (see FIG. 4B, bottom, arrow), but not typically to a degree which compromises the stability. Furthermore, most EPW controllers are programmable, allowing the turning speed during high forward velocities to be modified, and ameliorating the risk of lateral tipping during these maneuvers.
Apart from stability, maneuverability is a second critical factor currently affecting POVs and EPWs that impacts the functionality of each device. As discussed above, the structural design of the POVs requires them to make large sweeping turns (see FIG. 4A). This restricts functional use of the POV to larger open spaces than are necessary for EPWs. Because of this limitation, POV users cannot readily maneuver in their homes or workplaces. Daily tasks such as maneuvering in front of a desk, or within the confined space of most bathrooms would be possible with an EPW, but not with a POV. This is one of the primary reasons that POVs are provided strictly to individuals who have some ability to ambulate within their home.
A third critical factor for both the consumer and health insurers is the cost of the vehicle. While stability and maneuverability of POVs is lower compared to EPWs, POVs cost significantly less.
What is critically needed is a new personal vehicle which meets the needs of these individuals with disabilities or who otherwise have a mobility impairment (e.g., from advanced age), but is also low-cost, thus helping to curb rising healthcare costs. The present invention provides a low cost personal vehicle which performs similarly to an EPW, but is priced similarly to a POV.